Multilayer polypropylene films and methods of making and using the same

Abstract

A method including forming a bilayer polymer film having an oriented polypropylene film and a metallocene-catalyzed polypropylene film wherein the metallocene-catalyzed polypropylene film has a seal initiation temperature of from 80° C. to 130° C. A laminate including a biaxially oriented polypropylene film, a metallocene-catalyzed polypropylene film, and a substrate, wherein the metallocene-catalyzed polypropylene film is disposed between the biaxially oriented polypropylene film and the substrate.

What is claimed is: 
     
       1. An article produced by a method comprising:
 forming a bilayer polymer film comprising a biaxially oriented polypropylene film and a metallocene-catalyzed polypropylene film, wherein the metallocene-catalyzed polypropylene film has a seal initiation temperature of between 105° C. and 120° C., wherein the metallocene catalyzed polypropylene film comprises metallocene catalyzed ethylene-propylene random copolymer having a melt flow rate of from 10 g/10 min to 500 g/10 min, and wherein the laminate does not include a tie layer between the biaxially oriented polypropylene film and the metallocene-catalyzed polypropylene film. 
 
     
     
       2. A laminate comprising:
 a biaxially oriented polypropylene film, a metallocene-catalyzed polypropylene film, and a substrate, wherein the metallocene-catalyzed polypropylene film is disposed between the biaxially oriented polypropylene film and the substrate, and wherein the metallocene-catalyzed polypropylene film has a seal initiation temperature of from 105° C. to 130° C., wherein the metallocene-catalyzed polypropylene film has a seal initiation temperature of between 105° C. and 120° C., wherein the metallocene-catalyzed polypropylene film comprises metallocene catalyzed ethylene-propylene random copolymer having a melt flow rate of from 10 g/10 min to 500 g/10 min, and wherein the laminate does not include a tie layer between the biaxially oriented polypropylene film and the metallocene-catalyzed polypropylene film. 
 
     
     
       3. The laminate of  claim 2 , wherein the metallocene-catalyzed polypropylene film has a seal initiation temperature of from 105° C. to 120° C. 
     
     
       4. The laminate of  claim 2 , wherein the laminate  1   s  substantially free of ethylene-vinyl-acetate. 
     
     
       5. The laminate of  claim 2 , wherein the biaxially oriented polypropylene film is subjected to a surface modification process. 
     
     
       6. The laminate of  claim 5 , wherein the surface modification process comprises corona treatment, flame treatment, or plasma treatment. 
     
     
       7. The laminate of  claim 2 , wherein the substrate is paper, plastic, metal, wood, fabric, glass, or combinations thereof. 
     
     
       8. The laminate of  claim 2 , wherein the laminate exhibits an adhesive strength of from 0.1 lb f  to 10 lb f  based on a 180° peel strength test. 
     
     
       9. The laminate of  claim 2 , wherein the laminate comprises less than 1 weight percent ethylene-vinyl-acetate. 
     
     
       10. The article of  claim 1 , wherein the metallocene-catalyzed polypropylene film has a seal initiation temperature of from 105° C. to 120° C. 
     
     
       11. The article of  claim 9 , wherein the metallocene-catalyzed polypropylene film comprises metallocene catalyzed ethylene-propylene random copolymer having a melt flow rate of from 10 g/10 min to 500 g/10 min, wherein the bilayer polymer film does not include a tie layer between the oriented polypropylene film and the metallocene-catalyzed polypropylene film, and wherein the bilayer polymer film has a haze percentage of from 1.5% to 7%. 
     
     
       12. A bilayer film comprising:
 a biaxially oriented polypropylene film; and 
 a metallocene-catalyzed polypropylene film, wherein the metallocene-catalyzed polypropylene film has a seal initiation temperature of between 105° C. and 120° C., wherein the metallocene-catalyzed polypropylene film comprises metallocene catalyzed ethylene-propylene random copolymer having a melt flow rate of from 10 g/10 min to 500 g/10 min, and wherein the laminate does not include a tie layer between the biaxially oriented polypropylene film and the metallocene-catalyzed polypropylene film.